1. Field of the Invention
The present invention relates to a microprobe structure, particularly to a three-dimensional microprobe array assembly structure with depth and angle detection.
2. Description of the Related Art
Probes have been widely used in many fields, such as biochips and semiconductor tests. With the advance of science and technology, test samples are also being miniaturized, and probes thus require higher precision. Hence, more and more personnel have been devoted to related researches and developments.
Daryl R. Kipke et al. published in IEEE a “Silicon Substrate Intracortical Microelectrode Array for Long-Term Recording of Neuronal Spike Activity in Cerebral Cortex”, which is a single-piece edge-type microprobe array, wherein IC is built in the probe substrate. Its disadvantage is that additional substrate area needs preparing for probes in IC fabrication. Thus, the area and cost increases. Besides, it does not reveal the design of a three-dimensional probe array.
Qing Bai et al. proposed a “High-Yield Microassembly Structure for Three-Dimensional Microelectrode Arrays”, wherein general single-piece edge-type microprobe arrays are sequentially inserted into the pre-fabricated holes of a substrate. Such a technology can indeed achieve a three-dimensional microelectrode array. However, the joint of the single-piece edge-type microprobe arrays and the substrate needs ultrasonic welding, which increases technical complexity. Further, such an assembly structure also has the disadvantages of the single-piece edge-type microprobe array—bulky volume and higher cost.
A Taiwan patent No. I224676 disclosed a “Method for Fabricating a Three-Dimensional Probe Array”, wherein a stack of a three-dimensional probe array is formed with several cycles of exposures and developments. However, the more cycles of exposures and developments, the greater the accumulated alignment error. Besides, the probe of this technology cannot have several independent sensing electrodes, which the probe of a general edge-type microprobe array should have.
On the whole, the abovementioned prior arts are all unlikely to detect depths and angles. Thus, the reliability of measurement is influenced, which will be a big problem in detecting a miniature object.